CN102819369B - Method for Improving Accuracy of Touch Coordinate Calculation in Capacitive Multi-touch System - Google Patents

Abstract

The invention provides a method for improving the calculation accuracy of touch coordinates of a capacitive multi-point touch panel system, which sequentially comprises the following steps: after initializing the driving detection device and the analog-digital conversion device, driving and detecting the capacitive touch panel to generate image raw data, converting the image raw data into digital image raw data by the analog-digital conversion device, sequentially performing denoising and linearity increasing operations on the digital image raw data by the control device to generate linearized raw data, performing integral accumulation operations on the linearized image raw data to generate integral image raw data, performing accumulated error removing operations on the integral image raw data to generate accumulated error removed image raw data, and performing touch coordinate calculation according to the accumulated error removed image raw data. The method effectively improves the calculation accuracy of the touch coordinate of the capacitive multi-point touch panel and improves the signal-to-noise ratio.

Description

Method for Improving Accuracy of Touch Coordinate Calculation in Capacitive Multi-touch System

technical field

The invention relates to the technical field of touch panels, in particular to a method for improving the calculation accuracy of touch coordinates of a capacitive multi-touch system.

Background technique

Most modern consumer electronic devices are equipped with touch pads as one of their input devices. In order to meet the needs of lightness, thinness, shortness, and smallness, the touch panel is also integrated with the panel to form a touch panel, which is convenient for users to input. According to different detection principles, touch panels can be divided into four types: resistive, capacitive, acoustic, and optical. Among them, capacitive touch panels are the most common at present.

The general driving method of the capacitive touch panel is to detect the capacitance of each conductor line to the ground, and judge whether there is an object approaching the capacitive touch panel by the change of the capacitance value to the ground. This is the existing self-inductance capacitance (self capacitance) detection, wherein the self-induction capacitance or ground capacitance is not a physical capacitance, but the parasitic and stray capacitance of each conductor line. 1 is a schematic diagram of the existing self-inductance capacitance (self capacitance) detection. In the first time period, the conductor line in the first direction is first driven by the driver and detector 110 in the first direction, so as to control the conductor in the first direction. The self-sensing capacitance of the line is charged. Then during the second time period, the driving and detector 110 detects the voltage on the conductor line in the first direction. Also in the third time period, the driving and detector 120 of the second direction drives the conductor lines of the second direction, so as to charge the self-induction capacitance of the conductor lines of the second direction. Then in the fourth time period, the driving and detector 120 detects the voltage on the conductor line in the second direction.

In the existing self-induction capacitance (self capacitance) detection method in Fig. 1, a driving circuit and a detection circuit are connected simultaneously on the same conductor line, and after the conductor line is driven first, the variation of the signal is detected on the same conductor line, and then Determine the size of the self-sensing capacitor. Its advantages are less data volume, quick acquisition of frame row data, and lower power consumption. Its disadvantages are that it is easy to cause misjudgment of touch points due to floating conductors on the touch panel, and multiple There will be ghosting phenomenon when touching. That is, if the actual touch position is position A and position B as shown in the figure, there will be two other non-actual touch positions, position A' and position B', and position A' and position B' are position A, "Ghosting" at position B.

The method for driving the capacitive touch panel is to detect the change in the size of the mutual capacitance (mutual capacitance, Cm) to determine whether there is an object close to the touch panel. Similarly, the mutual capacitance (Cm) is not the physical capacitance, it is the first The mutual induction capacitance (Cm) between the conductor lines in one direction and the conductor lines in the second direction. FIG. 2 is a schematic diagram of existing mutual induction capacitance (Cm) detection. As shown in FIG. 2, the driver 210 is arranged in the first direction (Y), and the detector 220 is arranged in the second direction (X). During the first half period of the period T1, the driver 210 drives the conductor line 230 in the first direction, and uses the voltage Vy_1 to charge the mutual induction capacitor (Cm) 240. During the second half period of the first time period T1, all detectors 220 detect all The voltage (Vo_1, Vo_2, . . . , Vo_n) on the conductor line 250 in the second direction is used to obtain n data, and after m driving cycles, m×n data can be obtained. In an actual system, the drivers 210 and detectors 220 are in the same integrated circuit to save cost.

The advantage of the mutual induction capacitance (Cm) detection method is that the signals of the floating conductor and the grounding conductor are in different directions, so it can be easily judged whether it is human body contact. At the same time, due to the real coordinates of each point, when multiple points are touched at the same time, the real position of each point can be distinguished, and the mutual capacitance (Cm) detection method can easily support the application of multi-touch.

However, when an object approaches or touches the touch panel, the voltage signal detected by the detector 220 will vibrate seriously due to the noise generated by the human body, the environment, and the panel, resulting in instability of the calculated touch coordinates. This greatly reduces the Signal to Noise Ratio (SNR) of the entire touch system. At the same time, in an actual touch system, when there is a touch in the direction generally referred to as the detection line (ie, the Y direction), noise is likely to be generated, which affects the accuracy of touch coordinate calculation. Therefore, there is still room for improvement in the existing technology for detecting capacitive touch panels.

Contents of the invention

The purpose of the present invention is mainly to provide a method for improving the calculation accuracy of touch coordinates of a capacitive multi-touch system, so as to increase the calculation accuracy of touch coordinates and improve the signal-to-noise ratio (SNR) of the system.

According to a characteristic of the present invention, the present invention proposes a method for improving the calculation accuracy of touch coordinates of a capacitive multi-touch system. The system includes a capacitive touch panel, a drive detection device, and an analog-to-digital conversion device. , and a control device, the capacitive touch panel includes n columns of sensing lines and m rows of driving lines, and the driving detection device includes m drivers and n detectors for performing capacitive driving and detection respectively, the simulation A digital conversion device is connected to the drive detection device to perform analog-to-digital conversion, and the method includes: (A) the control device performs initialization on the drive detection device and the analog-to-digital conversion device ; (B) the driver and detector in the drive detection device drive and detect the capacitive touch panel respectively to generate image raw data (image raw data); (C) the analog digital The conversion device converts the image raw data (image raw data) into digital image raw data (digital image raw data); (D) the control device executes the digital image raw data (digital image raw data) denoising and adding linearity operations to generate linearized image raw data; (E) the control device performs integral accumulation operations on the linearized image raw data (linearized image raw data), to Generating integral image raw data (integrated image raw data); (F) the control device performs a clearing accumulation error operation on the integral image raw data (integrated image raw data), so as to clear the integrated image raw data (integrated image raw data ) to generate de-accumulated error image raw data; and (G) the control device performs touch coordinate calculation according to the accumulated error image raw data to generate a touch on the capacitive touch panel coordinate value.

According to another characteristic of the present invention, the present invention proposes a capacitive multi-touch system, which includes a capacitive touch panel, a drive detection device, an analog-to-digital conversion device, and a control device. The capacitive touch panel has m rows of driving lines and n columns of sensing lines. The drive detection device includes m drivers and n detectors connected to the capacitive touch panel for respectively performing capacitive drive and detection to generate original image data. The analog-to-digital conversion device is connected to the drive detection device, and is used for analog-to-digital conversion of the original image data to generate original digital image data. The control device is used to execute steps (D)-(E) in the method.

The method of the present invention can effectively improve the calculation accuracy of the touch coordinates of the capacitive multi-touch panel by considering the problems of noise and increasing linearity and reducing the accumulation error caused by common noise.

Description of drawings

FIG. 1 is a schematic diagram of an existing self-inductive capacitance detection;

FIG. 2 is a schematic diagram of existing mutual induction capacitance detection;

3 is a block diagram of a capacitive multi-touch system of the present invention;

4 is a flowchart of a method for improving the accuracy of touch coordinate calculation of a capacitive multi-touch panel according to the present invention;

Fig. 5 is the detailed flow chart that the present invention carries out denoising and increases linearity operation;

Fig. 6 is a schematic diagram of performing denoising and increasing linearity operations in the present invention;

7 is a schematic diagram of the operation of the first detector in the drive detection device 320 of the present invention;

Fig. 8 is a schematic diagram of the present invention performing integration and accumulation operations;

FIG. 9 is a detailed flowchart of the operation of clearing accumulated errors in the present invention.

[Description of main components and symbols]

Driver and Detector 110 Driver and Detector 120 Driver 210 Detector 220

Conductor wire in the first direction 230 Conductor wire in the second direction 240

Low standby power drive system for capacitive multi-touch 300

Capacitive touch panel 310 Drive detection device 320

Analog-to-digital conversion device 330 Control device 340

First conductor wire 311 Second conductor wire 312

storage unit 341

Detailed ways

FIG. 3 is a schematic diagram of the capacitive multi-touch system of the present invention. The capacitive multi-touch system 300 includes a capacitive touch panel 310 , a driving detection device 320 , an analog-to-digital conversion device 330 , and a control device 340 .

The capacitive touch panel 310 has m first conductor lines 311 (including Y1-Y6 . . . ) distributed in the first direction (Y) and n second conductor lines 311 distributed in the second direction (X). Conductor lines 312 (including X1-X6 . . . ), the first conductor line 311 is used as a driving line, and the second conductor line 312 is used as a sensing line. The driving detection device 320 is connected to the capacitive touch panel 310 to perform capacitive driving and detection to generate original image data. The driving detection device 320 includes m drivers and n detectors (not shown in the figure) , to respectively correspond to m first conductor lines 311 and n second conductor lines 312 , that is, each conductor line 311 is connected to a driver, and each second conductor line 312 is connected to a detector. The analog-to-digital conversion device 330 is connected to the detector in the drive detection device 320 for performing analog-to-digital conversion on the original image data to generate original digital image data. The control device 340 may have a storage unit 341 for temporarily storing data such as image raw data generated during the detection of the capacitive touch panel 210 by the drive detection device 320 and obtaining touch coordinates. The control device 340 calculates touch coordinates on the capacitive touch panel 210 according to image raw data.

FIG. 4 is a flowchart of a method for improving the calculation accuracy of touch coordinates of a capacitive multi-touch panel according to the present invention. Firstly, in step (A), the control device 340 initializes the drive detection device 320 and the analog-to-digital conversion device 330 . Which includes initialization setting of the driving detection device 320 when mutual capacitance (mutual capacitance) or self capacitance (self capacitance) driving detection, parameters such as the number of driving waveforms, frequency, type, and setting of the analog-to-digital conversion device 330 working frequency.

In step (B), the driver and the detector in the driving detection device 320 respectively drive and detect the capacitive touch panel 310 to generate image raw data. The drive detection device 320 can perform mutual capacitance (mutual capacitance) drive and detection, and can also perform self-capacitance (self capacitance) drive and detection to generate the image raw data. The capacitive touch panel 310 is driven and detected, that is, each driver in the driving detection device 320 is loaded with a driving electric signal to each first conductor line 311 connected to it, and each detector is used to detect The output electrical signal on each second conductor line 312 when the mutual capacitance Cm or the self capacitance Cs changes.

In step (C), the analog-to-digital conversion device 330 converts the image raw data (image raw data) into digital image raw data (digital image raw data); the digital image raw data (digital image raw data) can be stored in the The storage unit 341 is used for subsequent processing by the control device 340 . Wherein, since there are m rows of first conductor lines 311 and n columns of second conductor lines 312, therefore, the position at the intersection of the first conductor lines 311 and the second conductor lines 312 corresponds to a piece of digital image raw data, each of the second The conductor lines 312 correspond to m pieces of original digital image data. Therefore, the original digital image data corresponding to the entire capacitive touch panel has m rows and n columns, totaling m×n pieces.

In step (D), the control device 340 performs denoising and linearity addition operations on the digital image raw data to generate linearized image raw data.

FIG. 5 is a detailed flow chart of performing denoising and increasing linearity operations in the present invention. The capacitive touch panel has n columns of sensing lines, each column of sensing lines intersects with m rows of driving lines, and there are m positions, which correspond to m pieces of digital image raw data. Therefore, each column of sensing lines can be Each piece of digital image raw data corresponding to the position is the processing object, and the following steps are performed to obtain the linearized raw data corresponding to the entire capacitive touch panel. The details are as follows:

In step (D1), the control device 340 reads the original digital image data of the Nth position in one of the sensing lines (column) from the storage unit 341, wherein, N=1, 2, . . . , m .

In step (D2), it is judged whether the original digital image data of the Nth position exceeds a threshold Th. The critical value Th is obtained from a large number of statistics of raw digital image data generated when there is a touch.

In step (D3), if it is determined in step (D2) that the original digital image data of the Nth position exceeds the critical value Th, the original digital image data of the Nth position is retained.

In step (D4), if step (D2) judges that the digital image raw data of the Nth position does not exceed the critical value Th, then judge the digital image at the position adjacent to the Nth position in the row Whether the original data exceeds the critical value Th. Wherein, the original digital image data adjacent to the Nth position can be, for example, the original digital image data corresponding to two positions above or two positions below the Nth position in the row. That is, the original digital image data corresponding to the N-1th position and the N-2th position in the same row, or the digital image original data corresponding to the N+1th position and the N+2th position respectively. In another embodiment of the present invention, the original digital image data corresponding to the N-1th position, the N-2th position, and the N-3th position in the same column can be selected, or the N+1th position The original digital image data corresponding to the position, the N+2th position, and the N+3th position respectively. In other words, according to actual needs, digital image raw data corresponding to several positions above or below the Nth position can be selected.

If the step (D4) judges that in the column, the original digital image data at the position N adjacent to the Nth position exceeds the critical value Th, then keep the original digital image at the Nth position in step (D3). data, if not, then in step (D5), the original digital image data of this Nth position is cleared and reset to 0; afterward, in step (D6), change the next column, and perform step (D2)- (D4).

FIG. 6 is a schematic diagram of denoising and increasing linearity operations performed by the present invention. In this schematic diagram, the critical value Th is 200. As shown in FIG. 6 , in the second column of sensing lines, there are m positions intersecting with m driving lines, therefore, there are m pieces of original digital image data. There is a touch phenomenon at positions A to F, so the value of the original data of the digital image is relatively high. In the 10th row of driving lines, there are also m pieces of digital image raw data. There is a touch phenomenon from position A' to position B'. Since one of the original digital image data 250, 250 corresponding to A, B above the positions C and D is greater than the critical value 200, the original digital image data corresponding to positions C and D, 150, 120, are retained. Because one of the original digital image data corresponding to the two positions below position E has a digital image original data of 213, which is greater than the critical value of 200, the original digital image data 110 corresponding to position E is also reserved, and the corresponding position F is reserved in the same way. raw digital image data. Because one of the original digital image data 250, 250 corresponding to the two positions A, B above the position C', D' is greater than the critical value Th, the original digital image data 150, 120 of the position C', D' is retained. For position E', none of the original digital image data corresponding to the upper two positions and the original digital image data corresponding to the lower two positions is greater than the critical value 200, so the original digital image data corresponding to this position is cleared from 110 and reset to 0 .

In the prior art, when the original digital image data at positions C, D, C', and D' is less than the critical value Th, the data at positions C, D, C', and D' are set to 0, So easy to create discontinuities. It can be seen from Figure 6 that although the original digital image data of positions C, D, C', and D' are smaller than the critical value Th, they still retain their original digital image data, thereby increasing the linearity and avoiding discontinuity .

In step (E), the control device 340 performs integration and accumulation operations on the linearized image raw data to generate integrated image raw data, which is temporarily stored in the storage unit 341 middle.

The drive detection device 320 has n detectors, and each detector subtracts the two linearized image raw data (linearized image raw data) data at the upper and lower positions of the detected sensing line to reduce common noise. . FIG. 7 is a schematic diagram of the operation of the first detector in the driving detection device 320 of the present invention. As shown in Figure 7, it is the second linearized image original data D(2,1) minus the first linearized image original data D(1,1), the third linearized image original data D(3 , 1) Subtract the second linearized image raw data D(2,1), ... the mth data D(m, 1) minus the m-1th data D(m-1, 1), m is the number of drives, and so on. Therefore, in step (E), it is necessary to perform an integral accumulation operation on the linearized image raw data.

The integrated image raw data (integrated image raw data) has m×n items. FIG. 8 is a schematic diagram of performing integration and accumulation operations in the present invention. That is, the capacitive touch panel 310 is first detected by the drive detection device 320, and the detected voltage is converted into digital image raw data (digital image raw data) by the analog-to-digital conversion device 330, and the digital image The original data (digital imageraw data) can be de-noised and linearized to obtain the more stable and linearized image raw data (linearized image raw data), and then through the integration and accumulation operation, each The signal of one detector, or the signal of each channel (channel).

In other embodiments, step (E1) may be performed after step (E). Step (E1) is to perform a sign inversion operation on the original integral image data generated in step (E), so as to facilitate subsequent operations.

In step (F), the control device 340 executes a clearing accumulation error operation on the integral image raw data (integrated image raw data) to clear the accumulation error in the integral image raw data (integrated image raw data) to generate To accumulate error image raw data (cumulative error image rawdata).

FIG. 9 is a detailed flowchart of the operation of clearing accumulated errors in the present invention. In step (F1), the control device 340 reads a total of m pieces of linearized image raw data in a column of sensing lines from the storage unit 341 .

In step (F2), the control device 340 judges whether the last piece of linearized image raw data in the row is similar to the penultimate piece of linearized image raw data in the row. This step can be realized by means of a first threshold Threshold1. When the absolute value of the difference between the last piece of linearized image raw data and the penultimate piece of linearized image raw data in the row is less than a first threshold value Threshold1, then it is determined that the last piece of linearized image raw data in the row and The raw data of the penultimate linearized image in the column is similar.

In step (F3), if it is determined that the last piece of linearized image raw data in the column is similar to the penultimate linearized image raw data in the column, the last linearized image raw data in the column is cleared and reset to 0 .

In step (F4), if it is determined that the last piece of linearized image raw data in the column is not similar to the penultimate linearized image raw data in the column, read the linearized image raw data in the Mth position of the column , where M=1, 2, . . . , m. Since the drive detection device 320 has m drivers, each detection line or column has m pieces of linearized image raw data.

In step (F5), it is judged whether the original linearized image data at the Mth position is the last linearized original image data in the column. If the original linearized image data at the Mth position corresponds to the original linearized image data corresponding to the mth drive, it is determined as the last piece of original linearized image data. M=1, 2...m.

In step (F6), if it is determined that the linearized image raw data at the Mth position is not the last linearized image raw data in the row, read the linearized image at the M+1th position in the row Raw data.

In step (F7), it is determined whether the original linearized image data at the Mth position is similar to the original linearized image data at the M+1th position. This step can be implemented specifically by means of the second threshold value Threshold2, when the absolute value of the difference between the original linearized image data at the Mth position and the original linearized image data at the M+1th position is less than one second When the threshold value is Threshold2, it is determined that the original linearized image data at the Mth position is similar to the original linearized image data at the M+1th position.

In step (F8), if it is determined that the original linearized image data at the Mth position is similar to the original linearized image data at the M+1th position, the original linearized image data at the Mth position is cleared and re- set to 0; and

In step (F9), read the linearized image raw data at the M+1th position of the row, and re-execute steps (F4)-(F8).

In step (F7), if it is determined that the original linearized image data at the Mth position is not similar to the original linearized image data at the M+1th position, step (F9) is executed.

In step (F5), if it is determined that the linearized image raw data of the Mth position is the last linearized image raw data of the row, the next row is changed in step (F10), and step (F1 ) to read the original m-pen of the linearized image in the next column of sensing lines.

In step (G), the control device 340 performs touch coordinate calculation according to the cumulative error image raw data to generate coordinate values on the capacitive touch panel.

The existing self-inductance capacitance (self capacitance) detection method or the mutual induction capacitance (Cm) detection method all use the driver 210 to input a signal, and through the capacitance change, the detector 220 detects different charges to generate a voltage signal, and then According to the change of the voltage signal, it is judged whether there is an object approaching or touching the touch panel. However, due to the noise generated by the human body, the environment, and the driver on the LCD panel, the detected voltage will have a serious change. At this time, the changed voltage value is converted into a digital signal by an analog-to-digital conversion device. The processing of filtering noise will cause errors and instability in coordinate judgment, resulting in a significant reduction in the signal-to-noise ratio (SNR) of the system.

The method for improving the calculation accuracy of the touch coordinates of the capacitive multi-touch system of the present invention is to remove the noise and increase the linearity of the original image raw data (image raw data) that has been shaken, and then perform the integration and accumulation operation , the signal of each detector or the signal of each channel (channel) can be obtained, and then the error value generated when the data is cleared and accumulated, and then processed by the coordinate calculation method to generate the coordinate position of the touch point, That is to judge more accurately whether there is a conductor or a finger touching the capacitive touch panel 310 .

Since the existing technology does not consider the noise and linearity issues, nor does it take into account that the detector will subtract the two data before and after to reduce the common noise (common noise), so it is impossible to filter the power supply noise or the first direction ( The noise changes generated by the first conductor lines 311 (Y1-Y6) distributed in Y) and the second conductor lines 312 (X1-X6) distributed in the second direction (X), thereby causing errors and instability in coordinate judgment When the situation occurs, the SNR of the system is greatly reduced. However, the method of the present invention can effectively improve the calculation accuracy of the touch coordinates of the capacitive multi-touch panel due to the consideration of the noise and the increase of the linearity problem and the reduction of the cumulative error caused by the common noise.

From the above, it can be known that the present invention, regardless of its purpose, means and efficacy, shows its features that are very different from the prior art, and it is of great practical value. However, it should be noted that the above-mentioned embodiments are only examples for convenience of description, and the scope of rights claimed by the present invention should be determined by the claims, rather than limited to the above-mentioned embodiments.

Claims (12)

1. promote the method for the touch coordinate accuracy in computation of capacitance type multi-point touch-control system for one kind, it is characterized in that, described capacitance type multi-point touch-control system includes a capacitance type touch-control panel, one drives pick-up unit, one analog-digital commutator, and a control device, wherein, described capacitance type touch-control panel comprises the n row line of induction and m row drive wire, described driving pick-up unit comprises m driver and n detecting device, drive in order to perform electric capacity respectively and detect, described analog-digital commutator is connected to described driving pick-up unit in order to perform Analog-digital Converter, described method comprises:

(A) described control device performs initialization to described driving pick-up unit and described analog-digital commutator;

(B) driver in described driving pick-up unit and detecting device drive described capacitance type touch-control panel respectively and detect, to produce image raw data;

(C) described image raw data is converted to digitized video raw data by described analog-digital commutator, and described digitized video raw data has the capable n row of m and amounts to m × n pen;

(D) described control device performs denoising to described digitized video raw data and increases linearity computing, to produce linearization raw data;

(E) described control device performs integration accumulating operation, to produce integration image raw data to described linearization image raw data;

(F) described control device performs described integration image raw data and removes add up error computing, to remove the add up error in described integration image raw data, to produce add up error image raw data; And

(G) go add up error image raw data to perform touch coordinate described in described control device foundation to calculate, and then produce the touch coordinate value on described capacitance type touch-control panel;

Wherein, described step (D) comprising:

(D1) the digitized video raw data of wherein N number of position in a row line of induction is read, wherein, N=1,2 ..., m;

(D2) judge that whether the digitized video raw data of described N number of position is more than a critical value;

(D3) if step (D2) judges that the digitized video raw data of described N number of position exceedes described critical value, then the digitized video raw data of described N number of position is retained; And

(D4) if step (D2) judges that the digitized video raw data of described N number of position does not exceed described critical value, judge in described row again, described critical value whether is exceeded with the digitized video raw data of adjoining position, described N number of position, if, then retain the digitized video raw data of described N number of position, if not, the digitized video raw data of described N number of position removed and be again set to 0;

(D5) the digitized video raw data of the N number of position in the wherein next column line of induction is read, wherein, N=1,2 ..., m, performs step (D2)-(D4).

2. method according to claim 1, it is characterized in that, distinguish corresponding digitized video raw data with the digitized video raw data of adjoining position, described N position for being positioned at N-1 position, a N-2 position described in same row, or corresponding digitized video raw data is distinguished in N+1 position, a N+2 position.

3. method according to claim 1, is characterized in that, step (F) comprising:

(F1) the linearization image raw data read wherein in a row line of induction amounts to m pen;

(F2) judge that in described row, whether finishing touch linearization image raw data is similar to the second last pen reciprocal described linearization image raw data in described row;

(F3) if judge, in described row, finishing touch linearization image raw data is similar to the linearization image raw data of the second last reciprocal in described row, removes finishing touch linearization image raw data in described row and is reset to 0;

(F4) the linearization image raw data of M position of described row is read, wherein, M=1,2 ..., m;

(F5) whether the linearization image raw data judging described M position is finishing touch linearization image raw data in described row;

(F6) if judge, the linearization image raw data of described M position is not as finishing touch linearization image raw data in described row, reads the linearization image raw data of the M+1 position of described row;

(F7) judge that whether the linearization image raw data of described M position is similar to the linearization image raw data of described M+1 position;

(F8) if judge, the linearization image raw data of described M position is similar to the linearization image raw data of described M+1 position, the linearization image raw data of described M position is removed and is reset to 0; And

(F9) read the linearization image raw data of M+1 position of described row, lay equal stress on and perform step (F4)-(F8).

4. method according to claim 3, it is characterized in that, in described step (F7), if judge the linearization image raw data of described M position and the linearization image raw data dissmilarity of described M+1 position, then perform step (F9).

5. method according to claim 3, it is characterized in that, in described step (F5), if judge the finishing touch linearization image raw data of the linearization image raw data of described M position as described row, then perform step (F1), to read the linearization image raw data in the next column line of induction.

6. method according to claim 3, it is characterized in that, in described step (F2), when the absolute value of the difference of the linearization image raw data of the second last reciprocal described in the image raw data of finishing touch linearization described in described row and described row is less than first threshold value, then judge that the image of finishing touch linearization described in described row raw data is similar to described the second last reciprocal linearization image raw data.

7. method according to claim 3, it is characterized in that, in described step (F7), when the absolute value of the difference of the linearization image raw data of described M position and the linearization image raw data of described M+1 position is less than second threshold value, then judge that the linearization image raw data of the linearization image raw data of described M position and described M+1 position is as similar.

8. a capacitance type multi-point touch-control system, is characterized in that, comprise:

One capacitance type touch-control panel, it has in m row drive wire and the n row line of induction;

One drives pick-up unit, comprises m driver and n detecting device, is connected to described capacitance type touch-control panel, drives in order to perform electric capacity respectively and detects, to produce image raw data;

One analog-digital commutator, is connected to described driving pick-up unit, in order to described image raw data is carried out Analog-digital Converter, to produce digitized video raw data; And

One control device, in order to driving pick-up unit and this analog-digital commutator described to perform initialization described in this, denoising is performed to this digitized video raw data described and increases linearity computing to produce a linearization image picture raw data, again integration accumulating operation is performed to produce an integration image raw data to this linearization image raw data described, the computing of removing add up error is performed to this integration image raw data described and goes add up error image raw data with the add up error removed in this integration image raw data described to produce, go add up error image raw data to perform touch coordinate according to described this to calculate, and then the coordinate figure produced on this capacitance type touch-control panel described,

Wherein, described control device performs denoising to described digitized video raw data and increases linearity computing and comprises to produce a linearization image picture raw data:

(D1) the digitized video raw data of wherein N number of position in a row line of induction is read, wherein, N=1,2 ..., m;

(D2) judge that whether the digitized video raw data of described N number of position is more than a critical value;

(D3) if step (D2) judges that the digitized video raw data of described N number of position exceedes described critical value, then the digitized video raw data of described N number of position is retained; And

(D4) if step (D2) judges that the digitized video raw data of described N number of position does not exceed described critical value, judge in described row again, described critical value whether is exceeded with the digitized video raw data of adjoining position, described N number of position, if, then retain the digitized video raw data of described N number of position, if not, the digitized video raw data of described N number of position removed and be again set to 0;

(D5) the digitized video raw data of the N number of position in the wherein next column line of induction is read, wherein, N=1,2 ..., m, performs step (D2)-(D4).

9. system according to claim 8, it is characterized in that, distinguish corresponding digitized video raw data with the digitized video raw data of adjoining position, described N position for being positioned at N-1 position, a N-2 position described in same row, or corresponding digitized video raw data is distinguished in N+1 position, a N+2 position.

10. system according to claim 8, it is characterized in that, described control device performs the computing of removing add up error to described integration image raw data and goes add up error image raw data to comprise with the add up error removed in this integration image raw data to produce:

(F1) the linearization image raw data read wherein in a row line of induction amounts to m pen;

(F2) judge that in described row, whether finishing touch linearization image raw data is similar to the second last pen reciprocal described linearization image raw data in described row;

(F3) if judge, in described row, finishing touch linearization image raw data is similar to the linearization image raw data of the second last reciprocal in described row, removes finishing touch linearization image raw data in described row and is reset to 0;

(F4) the linearization image raw data of M position of described row is read, wherein, M=1,2 ..., m;

(F5) whether the linearization image raw data judging described M position is finishing touch linearization image raw data in described row;

(F6) if judge, the linearization image raw data of described M position is not as finishing touch linearization image raw data in described row, reads the linearization image raw data of the M+1 position of described row;

(F7) judge that whether the linearization image raw data of described M position is similar to the linearization image raw data of described M+1 position;

(F8) if judge, the linearization image raw data of described M position is similar to the linearization image raw data of described M+1 position, the linearization image raw data of described M position is removed and is reset to 0; And

(F9) read the linearization image raw data of M+1 position of described row, lay equal stress on and perform step (F4)-(F8).

11. systems according to claim 10, it is characterized in that, in described step (F2), when the absolute value of the difference of the linearization image raw data of the second last reciprocal described in the image raw data of finishing touch linearization described in described row and described row is less than first threshold value, then judge that the image of finishing touch linearization described in described row raw data is similar to described the second last reciprocal linearization image raw data.

12. systems according to claim 10, it is characterized in that, in described step (F7), when the absolute value of the difference of the linearization image raw data of described M position and the linearization image raw data of described M+1 position is less than second threshold value, then judge that the linearization image raw data of the linearization image raw data of described M position and described M+1 position is as similar.